Add a Script
To add a a Project Library script, right click the Project Library item and click the New Script option.
Scripts and Packages
There are two main types of resources under the Project Library.
- Scripts - Each script resource can contain many functions and objects.
- Packages - Each package effectively acts as a folder, allowing you to better organize each script resource.
For example, let's suppose you added the following script module named
myFuncs, whose body is shown below.
Once we save our project, we can now call this function from anywhere within the project using the following syntax
For example, we could open the Script Console (Tools menu > Script Console), write the following, and execute the script.
Each script resource can contain multiple functions and objects. As you add new function definitions, the list on the right will populate giving you a quick way to navigate through long scripts.
Project Libraries and Execution
Because Python is a dynamic language, any code inside of a project library must be run to build the function and class definitions. This is a common behavior across interpreters. Within Ignition, these project libraries will run under certain conditions. For example, such as when the Script Console in the Designer starts up, if changes are made to third-party libraries inside of the gateway's installation directory, when saving changes to these project libraries, and several other conditions.
When this occurs, code inside of a project library is executed. Meaning classes and functions are defined, and any code that is not contained within either a class or function will execute.
Because of this process, it's generally recommended that all code within a project library is wrapped inside of a function or class definition.
Gateway Scripting Project
Project Library scripts are normally only accessible from the project they were defined in. Thus objects that exist in other scopes, such as Tags that exist in the Gateway scope, are unable to call Project Library scripts. Attempting to do so will result in Gateway log errors stating that "global name 'yourScript' is not defined'.
The exception to this rule is the Gateway Scripting Project. This project is specified by the Gateway Scripting Project property, which is set in the Config section of the Gateway Webpage under Gateway Settings. Entering in the name of a project under this property allows the Gateway access to Project Library scripts configured in the specified project.
Thus, if the myFuncs library in the prior section was configured in a project named "Tester"
We could use that name in the Gateway Scripting Project.
After we save, Tags and other Gateway-scoped resources can then start calling any of the scripts from our Project Library in the "Tester" project.